"We found no indication that intra-operative awareness with recall had any long-term effects on patients' psychosocial outcome," said Tanja Laukkala from Centre for Military Medicine in Helsinki, Finland.

The long-term follow-up study included nine patients with a documented episode of intra-operative awareness during general anaesthesia. All patients had ‘definite awareness with recall’ they accurately described events that occurred during their surgery.

A median of 17.2 years after their episode of intra-operative awareness, the patients were evaluated on a battery of tests of psychosocial well-being. Assessment included formal diagnostic interviews for PTSD, along with anxiety, depression, and other psychiatric disorders.

Nine patients with similar characteristics, who had undergone surgery without intra-operative awareness, were studied for comparison. The results showed no significant difference in psychosocial outcomes for the patients with and without intra-operative awareness.

In particular, none of the patients with intra-operative awareness were diagnosed with PTSD. In fact, in no patient did the episode of intra-operative awareness meet criteria for being a ‘potentially traumatic event’ of the type leading to PTSD.

Other measures of psychosocial well-being, including quality of life ratings, were also similar between groups. A few patients in each group had depression or other psychiatric disorders. Ongoing efforts needed to prevent intra-operative awareness with recall are an uncommon but documented complication in patients undergoing general anaesthesia.

Previous studies have suggested that intra-operative awareness may place patients at risk for PTSD and other mental health conditions, such as depression or alcohol abuse. The results suggest that intra-operative awareness does not necessarily increase the risk of PTSD and other mental health problems.